Answer:
 You may not think that Fruit Flies pose a health risk but they are insects and all insects pose a health risk if they hang around long enough.
Explanation:
 
        
                    
             
        
        
        
Carbon dioxide is released into the air... welcome if right :3 plz put a thx if im right
        
             
        
        
        
The penis is the male copulatory organ, so penis is the answer
        
                    
             
        
        
        
The correct answer is microglia. 
<span>Microglia is glial cells found in the central nervous system with the protective role. Because they are the resident macrophage cells, they act as the first and main form of active immune defense. Microglia is constantly cleaning the CNS for plaques, damaged or unnecessary neurons, and infectious agents, like viruses or other microorganisms.</span>